Age-dependent decrease in proliferation in the scale epidermis.

(A) Schematic view of the interscale and scale structures in the tail whole-mount epidermis. (B) Tail whole-mount epidermal sheets are stained with BrdU (proliferation marker, green) and Hoechst (blue). White dotted lines represent the boundary of scale and interscale. Asterisks represent hair follicles. Scale bars: 100 μm. (C, D) Quantification of BrdU-positive cells within each interscale and scale structure. The number of BrdU+ cells is scored from ≥8 interscale or scale IFE structures per mouse. N = 3. Error bars show S.E.M. Student’s t-test is used. **; P P = 0.22 (D). (E) BrdU (proliferation marker, green) and Hoechst (blue) staining in the tail skin sections. (F, G) Proportion of BrdU+ cells per basal cells in the scale (F) or interscale IFE (G). The number of BrdU+ cells is scored from ≥100 basal cells per mouse. N = 3. Student’s t-test. ns: not significant; **; P P = 0.31 (G).